Document handling device

ABSTRACT

In a document feeder for a copier with a stationary copying platen, having a document transport tray system movable towards and away from the copying platen for transporting original documents to the platen for copying by movement of the document transport over the platen from a position adjacent the platen, wherein the improvement includes one or more unidirectional document holding wheels engageable and disengageable by the movement of the document transport for holding the original documents against the platen in position for copying, and a document ejecting wiper connected to and movable with the document transport for wiping across the platen to thereby remove documents on the platen and for pushing those removed documents off of only one side of the platen while further documents are being transported onto the platen by the document transport, and while the holding wheels are disengaged, with the movement of the document transport towards the platen, the wiper and document transport being adapted to prevent the wiper from engaging those further documents being transported onto the platen by the document transport.

This invention relates to a simple and low cost original document sheetfeeder end ejector for a copier.

As copiers, particularly xerographic copiers, have increased in speedand applications, there has developed an increased need for apparatusand systems for sequential feeding of original documents to the copying(imaging) platen of the copier. As copiers themselves have become morecompact and of lower cost, such document handlers desirably are also.There are also many specialized copying applications for which there isa special document handling need. For example, as disclosed herein, thecapability of simultaneously feeding and ejecting a plurality oforiginal documents to a platen for simultaneous copying, especiallywhere those documents are envelopes, small sheets or cards. A desirablecombined feature is the automatic registering of the fed documents in adesired copying position on the platen.

Even with smaller and slower speed copiers it has become increasinglydesirable to provide at least semi-automatic document handling, in whichthe operator may initially load originals manually into an input of adocument handler, but the document handler then desirably automaticallyprovides the final feeding, deskewing and platen registration of thedocuments, and then automatically or semi-automatically ejects thedocuments after copying. These features are desirably all provided withas simple and low cost and compact a structure as possible.

A lightweight and removable document handler is particularly desirableto allow conventional manual copying on the same copier. That is, forthe document handler or feeder to be repositionable or removable toexpose the existing conventional transparent copying window (known asthe platen) of the copier. This allows the operator to manually place onthe same platen other documents, such as delicate or odd sized documentsor books.

Examples of patent literature generally relating to various aspects ofthis technology are cited and discussed below. All references citedherein, and their references, are incorporated by reference herein forappropriate teachings of additional or alternative details, features,and/or technical background.

Cross-referenced and also incorporated by reference herein is a commonlyfiled, commonly assigned, copending patent application by the sameinventor, U.S. Ser. No. 633,760, disclosing a copy sheet output slitterwhich may be used to automatically cut up copy sheets containing pluraldocument images from plural documents fed to the platen or copier forcopying onto a single copy sheet.

Of particular interest is U.S. Pat. No. 4,315,687 issued Feb. 16, 1982to Breuers et al. (Oce-Nederland). It discloses one example of copyinginformation from small plural original sheets simultaneously, and with amask (form overlay) for providing additional information on the copysheet. In Col. 1, line 54 it mentions subdividing the copy sheet.

The concept of positioning two documents on the platen for copyingsimultaneously onto a single copy sheet, and also a further disclosureof slitting the copying sheet into separate copies is disclosed in U.S.Pat. No. 3,402,628 to Redding. Note particularly the paragraph at thebeginning of Col. 1.

U.S. Pat. No. 3,288,459 issued Nov. 29, 1966 to A. M. Hitchcock et al.and 4,052,054 issued Oct. 4, 1977 to W. R. Cardwell et al. disclosed anoriginal document feeder for simultaneously feeding two originaldocuments to be copied simultaneously. The former illustrates andparticularly describes in Col. 3, middle, through Col. 4, a documenttray 2 with a reciprocating plate 54 adapted to hold two documents. Itplaces the documents on a moving belt transport 3 for transporting thedocuments through a downstream scanning station 4. The ejection of thedocuments is subsequently by that transport belt into a tray 92.

U.S. Pat. Nos. 4,367,947 and 4,368,977 were issued Jan. 11 and Jan. 18,1983, respectively, to N. K. Arter et al. (IBM). Both disclose a movingplaten copier in which unidirectional rollers 34, 35, provide forejection of a document from the moving platen in one direction ofmovement of the platen. Note, e.g. Col. 4, last paragraph through Col.5, last paragraph. Particularly also noted are the last lines of thisparagraph wherein a "movable scrapper blade or finger" is generallysuggested, but is not further described or illustrated. Nor is even anysuggestion made that the latter could be unidirectional or how it couldor would operate.

A unidirectional roller 72 is disclosed in a manual assist documentfeeder in U.S. Pat. No. 3,941,473 issued Mar. 2, 1976 to William Goffe.A unidirectional roller for a sheet stacker is disclosed in EuropeanPatent Application Publication No. 0 099 248 published Jan. 25, 1984 byR. W. Hughes et al.

U.S. Pat. Nos. 3,907,277 issued Sept. 23, 1975 and 3,944,366 issued Mar.16, 1976, both to Donald A. Robertson, show a sliding platen coverapparatus manually reciprocal relative to a copier platen for exchangingdocuments to be copied on the platen. Although the two structures inthese two patents differ, in both a document which has been copied isremoved from the platen by frictional engagement with the cover memberas it moves away from the platen. The documents are manually placed onthe platen for copying.

U.S. Pat. No. 3,988,065 issued Oct. 26, 1976 to R. P. Mileski et al. isnoted particularly for the small light reflective shields 60 associatedwith the document ejection drive wheels 30.

A typical commercial document feeder for a copier with a stationary (vs.moving) platen has a document transport means such as an endless belt totransport original documents to the platen for copying, and then toeject them, by movement of the document transport belt over the platenfrom a position adjacent the platen, such as disclosed, for example, inU.S. Pat. No. 4,428,666 issued Jan. 31, 1984 to R. L. Phelps et al, andthe numerous references cited therein.

U.S. Pat. No. 3,915,447 issued Oct. 28, 1975 to B. J. Perno, disclosesan endless belt document transport having a plurality of flexible tabson the belt for deskewing and registering and gripping document sheetsfor conveyance over the platen.

Examples of various other patents generally teaching known documenthandlers and copiers and control systems therefor, including documentand paper path switches and counters, are U.S. Pat. Nos.: 4,054,380;4,062,061; 4,076,408; 4,078,787; 4,099,860; 4,125,325; 4,132,401;4,144,550; 4,158,500; 4,176,945; 4,179,215; 4,229,101; 4,278,344;4,284,270 and 4,335,949. Conventional simple software instructions in acopier's conventional microprocessor logic circuitry and software ofdocument handler and copier control functions and logic, as taught bythe above and other patents and various commercial copiers, are wellknown and preferred. However, it will be appreciated that the functionsand controls described herein may be alternatively conventionallyincorporated into a copier utilizing any other suitable or known simplesoftware or hard wired logic systems, switch controllers, etc. Suitablesoftware for functions illustrated or described herein may varydepending on the particular microprocessor or microcomputer systemutilized, of course, but will be already available to or readilyprogrammable by those skilled in the art without experimentation fromthe descriptions and references provided herein.

The control of exemplary document and copy sheet handling systems may beaccomplished by conventionally actuating them by signals from thecontroller directly or indirectly in response to simple programmedcommands and from selected actuation or non-actuation of conventionalcopier switch inputs by the copier operator, such as switches selectingthe number of copies to be made in that run, selecting simplex or duplexcopying, selecting whether the documents are simplex or duplex,selecting a copy sheet supply tray, etc. The resultant controllersignals may conventionally actuate various conventional electricalsolenoid or cam controlled sheet deflector fingers, motors or clutchesin the copier in the selected steps or sequences as programmed.Conventional sheet path sensors, switches and bail bars, connected tothe controller, may be utilized for sensing and timing the positions ofdocuments and copy sheets, as is well known in the art, and taught inthe above and other patents and products. Copying systems utilize suchconventional microprocessor control circuitry with such connectingswitches and sensors for counting and comparing the numbers of documentand copy sheets as they are fed and circulated, keeping track of theirpositions, counting the number of completed document set circulationsand completed copies, etc. and thereby controlling the operation of thedocument and copy sheet feeders and inverters, etc.

The present invention desirably overcomes or reduces various of theproblems or limitations discussed above and/or in the cited references.

A preferred specific feature disclosed in this specification is toprovide, in a document feeder for a copier with a stationary copyingplaten having document transport means movable towards and away from thecopying platen of the copier for transporting original documents to theplaten for copying by movement of said document transport means over theplaten from a position adjacent the platen, wherein the improvementcomprises:

holding means, engageable and disengageable by movement of said documenttransport means, for holding the original documents against the platenin position for copying,

and document ejecting wiping means, connected to and movable with saiddocument transport means, for wiping across the platen to thereby removedocuments on the platen and for pushing those removed documents off ofonly one side of the platen while further documents are beingtransported onto the platen by said document transport means, and whilesaid holding means is disengaged, with said movement of said documenttransport means towards the platen,

said wiping means and said document transport means being adapted toprevent said wiping means from engaging further documents beingtransported onto the platen by said document transport means.

Additional specific features disclosed herein are such as wherein saidholding means for holding the original documents against the platen forcopying comprises a frictional wheel freely rotatable only in thedirection of said movement of said document transport means towards theplaten and vertically movable and positioned and biased to engage andpress downwardly against a document transported thereto by said documenttransport means, said frictional wheel resisting, by said engagement andby non-rotation, the movement of a document in the direction of movementof said document transport means away from the platen, so as to separatea document from said document transport means during said movementthereof away from the platen, and then to hold that document against theplaten;

wherein said holding means for holding the original documents againstthe platen for copying further comprises a flexible lightweightlight-reflective backing member extending over a document held againstthe platen by said frictional wheel and surrounding said frictionalwheel and vertically movable therewith for providing a document imagingbackground;

wherein said document transport means includes camming means forengaging and lifting said frictional wheel vertically away from saidplaten and away from said wiping means to provide said disengaging ofsaid holding means, and for rolling said frictional wheel onto saiddocument transport means so as to freely roll over a document on saiddocument transport means during said movement of said document transportmeans towards the platen;

wherein there are a plurality of independently operable and spaced apartsaid frictional wheels mounted over the platen for simultaneousregistrations of a plurality of documents on the platen and wherein saiddocument transport means is adapted to simultaneously feed a pluralityof documents toward the platen for individual engagement and retentionby said frictional wheels;

wherein said document transport means comprises a document supportingtray reciprocally movable over but spaced above the platen and adaptedto transport documents on top of said supporting tray, and said wipingmeans is mounted beneath said supporting tray;

wherein said wiping means comprises a brush mounted adjacent the side ofsaid document transport means adjacent the platen and extending fromsaid document transport means sufficiently to make a document sweepingengagement with the platen as said transport means moves over theplaten; and

wherein said brush dimensionally extends across the platen transversethe direction of movement of said document transport means.

Various of the above-mentioned and further features and advantages willbe apparent from the example described hereinbelow of one specificapparatus and its operation. The invention will be better understood byreference to the following description of this one specific embodimentthereof, which includes the following drawing figures (approximately toscale) wherein:

FIG. 1 is a perspective top view of one embodiment of an exemplarydocument feeding apparatus in accordance with the present inventionmounted on an exemplary commercial copier; and

FIGS. 2-4 are similar (schematic) side views of the exemplary documentfeeder of FIG. 1, showing this same feeder in three different positionsin its operation.

FIGS. 1-4 illustrate one example of the subject document feeder 10 forsequentially feeding document sheets to one example of a conventionalcopier 20 having a stationary conventional copying platen 22. The entiredocument feeder 10 is simply and easily mounted on top of anyconventional copier, when the existing platen cover or document handleris pivoted out of the way to expose the platen, as is conventionallyprovided for alternative manual document copying. The operation of thedocument feeder 10 is shown particularly in FIGS. 2-4. Documents may beloaded into a document transport 24 while that transport 24 is at oneside of the platen 22. The document transport 24 has a document holdingtray 26 on its upper surface into which a document or documents may beeasily loaded, and prealigned by a document rear edge stop or guide 28and side guides 30. The entire document transport 24 may then belinearly moved over the platen by means of its mounting guides. Herethese consist of two linear ball-bearing slides or tracks 32 and 34extending across the front and rear ends of the platen. These slides 32and 34 provide for smooth and reasonably accurate reciprocal movement ofthe document transport 24, from its initial position at one side of theplaten as in FIG. 2, to a position over the platen as in FIG. 3, and areturn back along the same path to the initial position as in FIG. 4.The slides 32, 34 are mounted at opposite ends to a left frame member 36and a right frame member 38. The left frame member 36 mounts over theleft side, here the registration edge, of the platen 22 and the rightframe member 38 has vertical end tabs which can fit into a slot in theupper cover of the copier, to the right of the platen, to provide anappropriate and easily removable mounting of the document feeder 10 tothe copier 20. The left frame member 36 may also have a hold-downbracket.

The reciprocal movement of the document transport 24 may be providedmanually by an operator handle 40, or by an appropriate motor drive,e.g. the double helex reciprocal lamp drive of the "Xerox" "4000" copierand U.S. Pat. No. 3,775,008.

It may be seen that the tray 26 of the document transport 24, and all ofits other moving components, with one exception, are spaced above theplaten 22 at all times during the reciprocal movement of the documenttransport 24. That one exception is a brush 42, which is mounted to thedocument transport 24, adjacent the front or platen side thereof andextending downwardly from the document transport 24. The brush 24extends laterally a sufficient width to extend substantially from thefront to the back of the entire platen, extending between the slides 32and 34. As the document transport 24 moves toward and over the platen,as in FIG. 3, the lower portion of the brush 24 engages and wipes acrossthe platen 22 to remove and eject any documents on the platen, pushingall removed documents off of only the left side of the platen into adocument ejection tray 44. Thus in each movement of the documenttransport 24 over the platen, any and all documents previously placed onthe platen are automatically ejected, without requiring any operatorintervention or action or any separate drives or mechanism.

In this same movement in which the document transport 24 automaticallyejects all the documents in the platen by a document ejecting wiper 42,the subsequent documents to be copied are automatically fed onto thesame platen 22. Yet there is no interference between these two functionswith the present system. The document wiping or brushing system and therest of the document transport 24 are so designed that the brush 42 isprevented from engaging any of the further documents beingsimultaneously transported onto the platen by the document transport 24.The brush 42 extends from beneath the tray 26 while the incoming furtherdocuments are transported on the top of the tray 26. These documents arenot released and placed on the platen from the document transport 24until the previous documents have already been swept therefrom by thebrush 42. Likewise on the return movement of the document transport 24the brush 42 slides back under the next document or documents beingplaced on the platen.

If desired, the brush 42 may be a known conductive, e.g. carbon fiber,brush to additionally provide platen static elimination.

Considering now the document platen placement and registration systemprovided here, this is also provided by a very simple structure. Amounting shaft 46 is provided extending over the platen from the frontand rear slides 32, 34. That is, from the outer, stationary, channelportions of these slides. Pivotally mounted to the shaft 46 over theplaten are weighted arms 48, having frictional wheels 50 pivotallymounted at their outer ends. There are three such arms 48, each with awheel 50, spaced over the platen here because this particular documentfeeder 10 is specifically adapted to simultaneously feed three smalldocuments, such as envelopes, statements or checks. Each wheel 50 has aone-way clutch only allowing for rotation of the wheels 50 in thedirection of the movement of the document transport 24 toward theplaten, as illustrated by the rotational arrows in the drawings. Eachweighted arm 48 independently biases and presses its wheel 50 downwardlyagainst a document transported thereunder by the document transport 24.Each wheel 50 is positioned to centrally engage, in the direction ofdocument movement, one individual document from the document transport24.

As particularly shown in FIGS. 2-4, the document transport 24 has a camsurface 52 at its front or platen-facing edge. The cam 52 is adapted toengage and lift up all of the wheels 50 (which independently pivot upvia their pivotally mounted arms 48) as the document transport is movedonto the platen under the shaft 46. The wheels 50 then freely roll upthe surface of the cam 52 and then roll over the surface of the tray 26and over any documents therein as long as the document transport 24 ismoving to the left, i.e. toward the platen. However, when the documenttransport 24 begins its reverse movement to the right, as in FIG. 4, thewrap spring, ratchet, or other conventional clutch associated with eachwheel 50 prevents its reverse rotation. Thus the wheel 50 isnon-rotatable in this direction of movement of the document transport 24and fully frictionally resists the reverse movement of the documentthereunder. As the wheels 50 are preferably urethane or other solid orforaminous high friction material, the document is held in positionunder the wheels 50 by this high frictional engagement. Thus the tray26, which has a lower coefficient of friction, provided, e.g., bypolished metal or plastic, slides out from under the now-retaineddocument, and the wheels 50 retaining that document.

As the document transport 24 is pulled further to the right, completelyout from under the wheels 50, the wheels 50 are now free to press thedocument down directly against the platen, and continue to hold thedocument in position on the platen until the entire document has beenreleased by the tray 26 and is resting on the platen. The downward anddownstream angle of the arms 48 provides an increased normal forcevector component increasing the pressure of the wheels 50 against thedocument as the document transport 24 is moved to the right.

This is also preferably assisted by large white opaque flexible plasticdocument covering members 51 fastened to the arms 48 and surrounding andextending from the wheels 50. These provide, in effect, miniatureflexible platen covers, here in the general shape of "mud flaps". Theyhelp hold the document flat and also cover areas of the platen notcovered by the document to provide a proper imaging background.

As noted above, the next or "new" documents are placed on the platenjust after, and with the same movement of the document transport 24, asthe previous or "old" documents were being removed by the brush 42. Atthe completion of one reciprocal cycle as in FIG. 4, the documenttransport is off to the right of the platen and the tray 26 is now emptyfor the loading of subsequent documents while the previous documents arebeing copied by the copier. The copying may be initiated conventionallymanually by a switch or foot pedal. Alternatively, copying may beinitiated automatically by a magnet on the document transport 24operating a reed switch on the copier when the document transport 24 isreciprocated over the platen, by passage of the magnet over the reedswitch. The magnetic reed switch may be at the side of the platen andconnected in parallel with the "START PRINT" button on the copier.

Skewing or mis-registration of the documents with this system isresisted by the plural parallel side guides 30 which, besides providingfor compartmentalized loading of individual documents, also keep theedges of the document aligned as the document transport 24 is pulledaway from the documents. Furthermore, by positioning each wheel 50 at adownstream area of the platen such that it engages a downstream area ofa document centrally of the document, as shown, the frictional forcesbetween the tray 26 and the document, as the tray 26 is pulled out fromunder the document, are providing a predominantly downstream pullingforce tending to deskew the document. The side guides 30 should, ofcourse, be parallel to the direction of movement of the documenttransport 24 to aid deskewing or resist skewing. Wider or double rollers50 may also be provided for this purpose.

The document retention and registration provided by the wheels 50 doesnot interfere with the ejection of the documents thereunder by the brush42 on the next reciprocal cycle of the document transport 24. That is,the pushing of the documents downstream by the brush 42 (to the leftside of the platen) is not resisted by the wheels 50, since they freelyrotate in that direction of movement of the document thereunder. Beforethe brush 42 reaches or contacts the wheels 50 themselves, they arecammed up over the top of the tray 26 by the cam 52. Thus, for the finalejection movement of the documents from the platen the wheels 50 andtheir attached flaps 51 are lifted totally away from the platen, and outof contact with any document thereon.

As the tray 26 is pushed towards the platen and under wheels 50, thereis a (relatively small) drag on the documents by the wheels 50 in their"free-wheeling" direction of rotation, plus a slight drag of the flaps51 on the documents. That is sufficient to automatically slide-registerthe rear (trail) edge of each document against the tray 26 rear guide26. That also automatically initially deskews each document in the tray26. The tray 26 has a fixed end-stop position of slides 32, 34 relativeto the platen, and the rear guide 28 is fixed relative to the tray 26.Therefore each document is accurately automatically pre-registered to arelative position on the platen.

Summarizing the above operation, plural documents prepositioned withinguides on a simple reciprocating tray adjacent the conventional fixedplaten of the copier are linearly transported on that tray over theplaten. There they are each engaged by a roller mounted in a fixedposition over the platen which freely rolls over a document in onedirection, but which is clutched so that upon the reverse movement ofthe tray the document is frictionally removed from the trayautomatically by the locked wheel and both are dropped onto the platenin proper copying position. Meanwhile, any documents previously placedon the platen have been removed in this same operation and movement by adocument ejecting brush wiping across the platen under but with thetray. With this system, document exchanges can take place as fast as theoperator can load documents and reciprocate the document transport 24.The individual documents may be more or less thrown in between theguides, i.e. with only very rough or crude initial orientation, yet thedocuments are placed in position in the platen with considerableaccuracy. They are removed from the platen automatically withoutrequiring any extra step or any additional time.

The present system is particularly suitable for documents which aredifficult to feed with automatic document feeders, such as envelopes ofvarious materials, thicknesses and contents. As shown here, asemi-automatic document feeder is provided in which documents areindividually loaded and fed. However, it will be appreciated that byappropriate modification of the tray 26, using known document feedingtechniques, that a stack or stacks of checks, slips, invoices or thelike may be placed in the tray 26 instead of individual documents. Thatis, with a front edge separating lip, or corners or front snubbers, orthe like, for the tray 26, the present system may be utilized forsequential feeding of the topmost sheet from one or more stacks ofsheets in the tray 26.

It will also be appreciated that both the wheels 50 with their arms 48may be readily repositioned, by sliding them along the shaft 46, toaccommodate different numbers or sizes of documents. Preferably thiswould be accompanied by a corresponding repositioning, or removing, ofside guides 30, so that each wheel 50 is positioned intermediately ofeach pair of opposing spaced side guides 30, as illustrated in FIG. 1.The number and position of the side guides 30 on the tray 26 providesappropriate subdivisions into plural narrow trays for the pluraldocument feeding to be provided. The number of arms 48 and wheels 50 maybe correspondingly increased or decreased.

A particular application of the present system is for generating threeU.S. Postal Service forms 3547 per copier cycle. This is accomplished bysimultaneously feeding three envelopes at a time, each with itsforwarding address sticker thereon, to the copier platen with thissystem. The platen is provided with a transparent forms overlaycontaining three sets of the appropriate additional printed informationnecessary to automatically generate three complete form 3547 postcardimages containing both the original address and forwarding addressinformation. A reduction (optically reduced image size) copy is made ofthe composite image of the form and the envelopes, which are over thetransparent areas of the form. Each single copy sheet, preferablyconventional letter size cardstock, containing these three compositeimages is then outputted from the copier through a slitter which cutsthat single sheet into three postcards, as further described in theabove-referenced commonly filed application by the same inventor.

While the embodiment disclosed herein is preferred, it will beappreciated that it is merely one example, and that variousalternatives, modifications, variations or improvements thereon may bemade by those skilled in the art from this teaching, which is intendedto be encompassed by the following claims.

What is claimed is:
 1. In a document feeder for a copier with astationary copying platen having document transport means movabletowards and away from the copying platen of the copier for transportingoriginal documents to the platen for copying by movement of saiddocument transport means over the platen from a position adjacent theplaten, wherein the improvement comprises:holding means, engageable anddisengageable by movement of said document transport means, for holdingthe original documents against the platen in position for copying, anddocument ejecting wiping means, connected to and movable with saiddocument transport means, for wiping across the platen to thereby removedocuments on the platen and for pushing those removed documents off ofonly one side of the platen while further documents are beingtransported onto the platen by said document transport means, and whilesaid holding means is disengaged, with said movement of said documenttransport means towards the platen, wiping means and said documenttransport means being adapted to prevent said wiping means from engagingsaid further documents being transported onto the platen by saiddocument transport means.
 2. The document feeder of claim 1 wherein saidholding means for holding the original documents against the platen forcopying comprises a frictional wheel freely rotatable only in thedirection of said movement of said document transport means towards theplaten and vertically movable and positioned and biased to engage andpress downwardly against a document transported thereto by said documenttransport means, said frictional wheel resisting, by said engagement andby non-rotation, the movement of a document in the direction of movementof said document transport means away from the platen, so as to separatea document from said document transport means during said movementthereof away from the platen, and then to hold that document against theplaten.
 3. The document feeder of claim 2 wherein said holding means forholding the original documents against the platen for copying furthercomprises a flexible lightweight light-reflective backing memberextending over a document held against the platen by said frictionalwheel and surrounding said frictional wheel and vertically movabletherewith for providing a document imaging background.
 4. The documentfeeder of claim 2 wherein said document transport means includes cammingmeans for engaging and lifting said frictional wheel vertically awayfrom said platen and away from said wiping means to provide saiddisengaging of said holding means, and for rolling said frictional wheelonto said document transport means so as to freely roll over a documenton said document transport means during said movement of said documenttransport means towards the platen.
 5. The document feeder of claim 2wherein there are a plurality of independently operable and spaced apartsaid frictional wheels mounted over the platen for simultaneousregistrations of a plurality of documents on the platen and wherein saiddocument transport means is adapted to simultaneously feed a pluralityof documents toward the platen for individual engagement and retentionby said frictional wheels.
 6. The document feeder of claim 5 whereinsaid document transport means includes camming means for engaging andlifting said frictional wheel vertically away from said platen and awayfrom said wiping means to provide said disengaging of said holdingmeans, and for rolling said frictional wheel onto said documenttransport means so as to freely roll over a document on said documenttransport means during said movement of said document transport meanstowards the platen.
 7. The document feeder of claim 1 wherein saiddocument transport means comprises a document supporting trayreciprocally movable over but spaced above the platen and adapted totransport documents on top of said supporting tray, and said wipingmeans is mounted beneath said supporting tray.
 8. The document feeder ofclaim 1 wherein said wiping means comprises a brush mounted adjacent theside of said document transport means adjacent the platen and extendingfrom said document transport means sufficiently to make a documentsweeping engagement with the platen as said transport means moves overthe platen.
 9. The document feeder of claim 8 wherein said brushdimensionally extends across the platen transverse the direction ofmovement of said document transport means.
 10. The document feeder ofclaim 8 wherein said document transport means comprises a documentsupporting tray reciprocally movable over but spaced above the platenand adapted to transport documents on top of said supporting tray, andsaid wiping means is mounted beneath said supporting tray.
 11. Thedocument feeder of claim 10 wherein said holding means for holding theoriginal documents against the platen for copying comprises a frictionalwheel freely rotatable only in the direction of said movement of saiddocument transport means towards the platen and vertically movable andpositioned and biased to engage and press downwardly against a documenttransported thereto by said document transport means, said frictionalwheel resisting, by said engagement and by non-rotation, the movement ofa document in the direction of movement of said document transport meansaway from the platen, so as to separate a document from said documenttransport means during said movement thereof away from the platen, andthen to hold that document against the platen, andwherein said documenttransport means includes camming means for engaging and lifting saidfrictional wheel vertically away from said platen and away from saidwiping means to provide said disengaging of said holding means, and forrolling said frictional wheel onto said document transport means so asto freely roll over a document on said document transport means duringsaid movement of said document transport means towards the platen.